<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>动画、形变</title>
    <style>
      .center {
        transform: translate(-50%, -50%);
      }
      .big {
        width: 500px;
        height: 500px;
        background-color: pink;
        border-radius: 50%;
        position: relative;
        overflow: hidden;
      }
      .middle {
        position: absolute;
        top: 50%;
        left: 50%;
        width: 450px;
        height: 450px;
        border-radius: 50%;
        background-color: lightgreen;
        z-index: 1;
      }
      .block {
        width: 250px;
        height: 500px;
        position: absolute;
        left: 250px;
        background-color: skyblue;
        transform: rotate(0deg);
        transform-origin: left;
        transition: all 3s;
      }
      .big:hover .block {
        transform: rotate(1080deg);
        background-color: #fff;
      }
    </style>
  </head>
  <body>
    <div class="big">
      <div class="middle center"></div>
      <div class="block"></div>
    </div>
  </body>
</html>
